<template>
  <el-menu :default-active="activeMenu" mode="horizontal" :ellipsis="false" @select="handleSelect">
    <template v-for="(item, index) in topMenus">
      <el-menu-item v-if="index < visibleNumber" :key="index" :style="{ '--theme': theme }" :index="item.path">
        <svg-icon v-if="item.meta && item.meta.icon && item.meta.icon !== '#'" :icon-class="item.meta.icon" />
        {{ item.meta.title }}
      </el-menu-item>
    </template>

    <!-- 顶部菜单超出数量折叠 -->
    <el-sub-menu v-if="topMenus.length > visibleNumber" :style="{ '--theme': theme }" index="more">
      <template #title>更多菜单</template>
      <template v-for="(item, index) in topMenus">
        <el-menu-item v-if="index >= visibleNumber" :key="index" :index="item.path">
          <svg-icon v-if="item.meta && item.meta.icon && item.meta.icon !== '#'" :icon-class="item.meta.icon" />
          {{ item.meta.title }}
        </el-menu-item>
      </template>
    </el-sub-menu>
  </el-menu>
</template>

<script setup>
import { constantRoutes } from '@/router'
import { isHttp } from '@/utils/validate'
import useAppStore from '@/store/modules/app'
import useSettingsStore from '@/store/modules/settings'
import usePermissionStore from '@/store/modules/permission'

// 顶部栏初始数
const visibleNumber = ref(null)
// 当前激活菜单的 index
const currentIndex = ref(null)
// 隐藏侧边栏路由
const hideList = ['/index', '/user/profile']

const appStore = useAppStore()
const settingsStore = useSettingsStore()
const permissionStore = usePermissionStore()
const route = useRoute()
const router = useRouter()

// 主题颜色
const theme = computed(() => settingsStore.theme)
// 所有的路由信息
const routers = computed(() => permissionStore.topbarRouters)

// 顶部显示菜单
const topMenus = computed(() => {
  const topMenus = []
  routers.value.map(menu => {
    if (menu.hidden !== true) {
      // 兼容顶部栏一级菜单内部跳转
      if (menu.path === '/' && menu.children) {
        topMenus.push(menu.children[0])
      } else {
        topMenus.push(menu)
      }
    }
  })
  return topMenus
})

// 设置子路由
const childrenMenus = computed(() => {
  const childrenMenus = []
  routers.value.map(router => {
    for (const item in router.children) {
      if (router.children[item].parentPath === undefined) {
        if (router.path === '/') {
          router.children[item].path = '/' + router.children[item].path
        } else {
          if (!isHttp(router.children[item].path)) {
            router.children[item].path = router.path + '/' + router.children[item].path
          }
        }
        router.children[item].parentPath = router.path
      }
      childrenMenus.push(router.children[item])
    }
  })
  return constantRoutes.concat(childrenMenus)
})

// 默认激活的菜单
const activeMenu = computed(() => {
  const path = route.path
  let activePath = path
  if (path !== undefined && path.lastIndexOf('/') > 0 && hideList.indexOf(path) === -1) {
    const tmpPath = path.substring(1, path.length)
    if (!route.meta.link) {
      activePath = '/' + tmpPath.substring(0, tmpPath.indexOf('/'))
      appStore.toggleSideBarHide(false)
    }
  } else if (!route.children) {
    activePath = path
    appStore.toggleSideBarHide(true)
  }
  // 仅设置侧边栏路由，不执行自动跳转（路由变化时的被动响应）
  activeRoutes(activePath, false)
  return activePath
})

function setVisibleNumber() {
  const width = document.body.getBoundingClientRect().width / 3
  visibleNumber.value = parseInt(width / 85)
}

function handleSelect(key, keyPath) {
  currentIndex.value = key
  const route = routers.value.find(item => item.path === key)
  if (isHttp(key)) {
    // http(s):// 路径新窗口打开
    window.open(key, '_blank')
  } else if (!route || !route.children) {
    // 没有子路由路径内部打开
    const routeMenu = childrenMenus.value.find(item => item.path === key)
    if (routeMenu && routeMenu.query) {
      const query = JSON.parse(routeMenu.query)
      router.push({ path: key, query: query })
    } else {
      router.push({ path: key })
    }
  } else {
    // 显示左侧联动菜单，并自动跳转到第一个二级路由（用户主动点击一级菜单）
    activeRoutes(key, true)
  }
}

/**
 * 激活路由并根据需要自动加载第一个二级路由
 * @param {string} key - 一级路由路径
 * @param {boolean} shouldAutoNavigate - 是否应该自动跳转到第一个二级路由，默认为 false
 * @returns {Array} 匹配的子路由数组
 */
function activeRoutes(key, shouldAutoNavigate = false) {
  const routes = []

  // 过滤出当前一级路由下的所有二级路由
  if (childrenMenus.value && childrenMenus.value.length > 0) {
    childrenMenus.value.map(item => {
      if (key == item.parentPath || (key == 'index' && '' == item.path)) {
        routes.push(item)
      }
    })
  }

  // 设置侧边栏路由
  if (routes.length > 0) {
    permissionStore.setSidebarRouters(routes)

    // 只有在明确指定需要自动跳转时才执行（通常是点击一级菜单时）
    if (shouldAutoNavigate) {
      // 自动跳转到第一个可用的二级路由
      const firstAvailableRoute = getFirstAvailableChildRoute(routes)
      if (firstAvailableRoute && route.path !== firstAvailableRoute) {
        // 使用 nextTick 确保路由更新在下一个事件循环中执行
        nextTick(() => {
          router.push(firstAvailableRoute).catch(err => {
            console.warn('自动跳转到第一个二级路由失败:', err)
          })
        })
      }
    }
  }

  return routes
}

/**
 * 获取第一个可用的子路由路径
 * @param {Array} routes - 子路由数组
 * @returns {string|null} 第一个可用的路由路径
 */
function getFirstAvailableChildRoute(routes) {
  for (const route of routes) {
    // 跳过隐藏的路由
    if (route.hidden) continue

    // 确保路由路径有效
    if (route.path && route.path !== '/') {
      let routePath = route.path

      // 确保路径以 / 开头
      if (!routePath.startsWith('/')) {
        routePath = `/${routePath}`
      }

      return routePath
    }
  }

  return null
}

onMounted(() => {
  window.addEventListener('resize', setVisibleNumber)
})

onBeforeUnmount(() => {
  window.removeEventListener('resize', setVisibleNumber)
})

onMounted(() => {
  setVisibleNumber()
})
</script>

<style lang="scss">
.topmenu-container.el-menu--horizontal > .el-menu-item {
  float: left;
  height: 50px !important;
  line-height: 50px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
}

.topmenu-container.el-menu--horizontal > .el-menu-item.is-active,
.el-menu--horizontal > .el-sub-menu.is-active .el-submenu__title {
  border-bottom: 2px solid #{'var(--theme)'} !important;
  color: #303133;
}

/* sub-menu item */
.topmenu-container.el-menu--horizontal > .el-sub-menu .el-sub-menu__title {
  float: left;
  height: 50px !important;
  line-height: 50px !important;
  color: #999093 !important;
  padding: 0 5px !important;
  margin: 0 10px !important;
}

/* 背景色隐藏 */
.topmenu-container.el-menu--horizontal > .el-menu-item:not(.is-disabled):focus,
.topmenu-container.el-menu--horizontal > .el-menu-item:not(.is-disabled):hover,
.topmenu-container.el-menu--horizontal > .el-submenu .el-submenu__title:hover {
  background-color: #ffffff;
}

/* 图标右间距 */
.topmenu-container .svg-icon {
  margin-right: 4px;
}

/* topmenu more arrow */
.topmenu-container .el-sub-menu .el-sub-menu__icon-arrow {
  position: static;
  vertical-align: middle;
  margin-left: 8px;
  margin-top: 0px;
}
</style>
